function setCookie(name,value)
{
    var Days = 30; 
    var exp  = new Date();    
    exp.setTime(exp.getTime() + 5*60*1000);
    document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
}
function getCookie(name)     
{
    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
     if(arr != null) return unescape(arr[2]); return null;

}
function delCookie(name)
{
    var exp = new Date();
    exp.setTime(exp.getTime() - 1);
    var cval=getCookie(name);
    if(cval!=null) document.cookie= name + "="+cval+";expires="+exp.toGMTString();
}